Personalized Nutrition

by karen on June 7, 2018

The Center for Science in the Public Interest (CSPI) is an activist group of healthcare professionals working hard to protect Americans and ensure science is considered by politicians when making public policy decisions. CSPI’s Nutrition Action Healthletter contains an article with the same title: “Personalized Nutrition”.  It provides an insightful review of companies offering personalized nutrition plans utilizing an individual’s DNA test.  Read further for a review and to know whether you should sign up to send in your mouth swab.



For $299, Habit will have you take the Habit Nutrition test, an online questionnaire about your height, weight, waist, blood pressure and activity level.  Before swabbing your cheek for the DNA sample, a 12-hour fast is required, then the consumption of their ‘Challenge Shake’, containing 950 calories, 18 teaspoons of added sugar, and more than half a day’s saturated fat.

The shake is designed to create a ‘unique metabolic challenge’ to find out how your body handles carbs, protein and fats.  You then obtain two blood samples with a fingerstick at different times after the Challenge Shake. Your results will arrive in up to six weeks.

Your genetic results are likely to give advice like “be mindful of your genes”, “due to how your body processes carbs, hidden sugars can have the wrong kind of impact”, and “you thrive on a wide variety of whole foods that are naturally nutrient-rich”.  You will receive information as to whether you are lactose intolerant or caffeine-sensitive, and get your levels of fasting blood sugar, triglycerides, and good cholesterol.

I probably don’t need to point out the obvious in that the advice is very generic vs genetic, that you likely don’t need a DNA test to tell you whether you have difficulty with dairy products or coffee, and a blood test through your primary care provider will give you blood sugar and cholesterol results, usually covered by insurance.

Viome offers “a personalized, easy-to-follow plan with precise diet, nutrition and supplement recommendations” based largely on the microbes in your gut.  For $399, you send in a stool sample to “enlist Viome to work for you today and join the wellness revolution”.

While the unique microorganisms that make up our digestive system is fascinating, and is being researched, we are, unfortunately, far from being able to assess our stomach bacteria, let alone give diet and lifestyle advice.  It is hard, even for researchers, to determine which bacteria and how much is in people’s digestive tract, and which type and how much is ideal for health.  There’s not yet enough evidence demonstrating that if you eat X or Y, you can change your gut microbiome, let alone that it could translate into some health outcome.

DayTwo is designed to devise diets that prevent spikes in post-meal blood sugar.  The research behind the company is impressive, but the risk for diabetes or cancer or heart disease cannot be assessed solely on blood sugar.  Nor can the type of diet that would promote the greatest weight loss.  Save the $349 fee until more work is done.


If you go to these websites, you may be impressed with the seeming plethora of research and facts based on research, and the professional look of the website.  A lot of money has been invested in the success of the company.  While a lot of good research has and is being done, the answers are just not yet there to provide personalized diets based on DNA.  These companies have overstepped the science and are making claims that aren’t true.

While we are all unique individuals with varying lifestyles, everyone would benefit from shifting to a veggie-rich diet that’s low in white flour and added sugars.  Working with a dietitian, we can personalize meal plans to design methods for implementing this simple yet effective dietary goal, and effectively help you achieve the personalized nutrition plan needed to succeed.


Karen Fisher, MS, RDN, CDE is a dietitian in Reno, Nevada, happily promoting the benefits of healthy foods at her nutrition consulting firm, Nutrition Connection. Find her website at

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